I hope noone minds me diggin up an old one, though I think it might be useful for newbies like me, reading through again...Quote:
Posted: Fri May 27, 2005
Diesel is very different to petrol in many ways, some are as follows..Quote:
Post subject: what is diesel?
im a bit of a newbie with all this mechanical stuff, so can someone please explain exactly what diesel means? Pros cons etc.
A diesel doesn't use spark plugs to set fire to the fuel/air mixture, instead it uses the nature of heat and gas to ignite it, when you let air out of a baloon or tyre, it's cold because it has just expanded, when you compress it, the opposite happens, it gets hot, thats how a diesel engine ignites the fuel air mix, by compressing it.
As a result the Diesel engine is simple no spark plugs means no leads, distributor, coil, or contacts/magnetic pickup. No battery or alternator is needed To keep it running, only to start it. Diesel engines are a lot more tolerant to being hosed down with water.
The Fuel is different and SAFER you can store and handle diesel easier. You can actually safely extinguish a candle flame by pouring diesel fuel over it (so long as it's not Euro winter diesel which is mixed with a little petrol) Diesel won't ignite until it is sprayed(atomised) or damn hot! Thats right throw matches into a puddle of standard diesel to extinguish them it works.
Rudolf Diesel invented the diesel engine to run on things like coal dust over 100 or so years ago, it runs on a wide range of fuels. Vegetable oils instead of mineral oils, thats the point, it was always meant to be an alternative to petrol. Diesel you buy at the servo is the oil companies invention, derived from oil, and can be temporarily set at a low price when too many people get veggie oil fever,(similar to monkeypox) and switch from petrol. When the fever has subsided because of the cheap petro-diesel, the price returns to normal.
Diesel engines have greater torque that is they climb hills at low engine revs and love it, petro-engines die (yes die!!! petro engines die!!!)
Diesel engines are built HEAVY and tough because the compression they use to ignite the fuel is 20ish-to-1, higher than the 7ish-to-1 used in p-engines for whatever reason...
Diesel engines START VERY DIFFERENTLY a petrol engine cranks and if everything is ok it goes, a diesel can crank happily at what sounds like a gleeful rate, and everything else is ok, and she won't start. The Secret to starting a diesel above all else, and lean close to your computer screen as i whisper, because not many people know this and get stuck with it, is cranking speed if you are cranking at 90% you'll be there all morning! Get the right battery with high CCA(cold cranking amps) good thick electrical leads, and when all else fails, TOW STARTING FIXES EVERYTHING such as sooted up glow plugs that are now insulated by soot and won't work, even though they are OK.
